Observational study. To evaluate the readability of commonly utilized patient-reported outcome measures (PROMs) in spine surgery. Although studies have evaluated patient education materials, discharge instructions, and informed consent forms in spine surgery, there is a dearth of literature on the readability of PROMs despite widespread health illiteracy. Without knowledge of PROM readability, it is unclear whether these measures are able to be understood by the average spine patient. We analyzed all commonly utilized nonvisual PROMs within the spinal literature and uploaded PROMs into an online readability calculator. The Flesch Reading Ease Score (FRES) and Simple Measure of Gobbledygook (SMOG) Index were collected. A FRES>79 or SMOG<7 was considered readable by the general population per American Medical Association and Centers for Disease Control guidelines. A stricter threshold recommended in health care (SMOG <6 or FRES>89) was then used to further review readability. Seventy-seven PROMs were included. Based on FRES, the mean readability of all PROMs was 69.2 ± 17.2 (range, 10-96.4), indicating an average eighth to ninth-grade reading level. The mean readability score categorized by the SMOG Index was 8.12 ± 2.65 (range, 3.1-25.6), representing an eighth-grade reading level. Compared with the reading level of the general population, 49 (63.6%) PROMs are written above the United States literacy level, according to FRES. Using stricter definitions of readability, 8 PROMs were considered readable, including PROM Information System pain behavior (FRES: 96.4 and SMOG: 5.2), PROM Information System sleep disturbance (SMOG: 5.6), Neck Pain and Disability Scale (SMOG: 4.3), and Zung Depression Scale (SMOG: 3.1). Most PROMs utilized in spine surgery require an average reading competency far above the average patient's comprehension. This may have a meaningful impact on understanding PROM instruments and may affect the accuracy of complete surveys and the rates of incompletion.